nice write up.

Question though, why couldnt we use a relay kit from a foglight kit...

Wish i knew how to make a board like that , If you can figure something for us that would be awesome....

 

Either a)Post all the part numbers or b) manufactuer them and charge.
I'd buy one !

 

Well you could if you install a new switch. The problem with the stock switch and that setup is that the stock switch is just a momentary push button so it will turn a relay on, but as soon as you lift your finger off the button the relay will turn off. You could do a two relay setup and have it loop on itself so it turns it on with the push button, but then it won't turn off with the pushbutton, it would only turn off by turning off the pwersource, ie the key.

There are other solutions to operate the lights, but this was the simplest I could come up with for using the existing switch and not cutting any wires.

 

so with your multimeter and all.... have you tried the "easy" way to hook up one wire from the headlight relay to the foglight relay to effectively short them together?

 

No because then the fog lights only come on with the headlight switch and always come on with the headlight switch. That would make the fog light button inopperable.

The switches in the cab send a signal to the ETACS-ECU which in turn sends a signal to the FRONT-ECU that controls all lights. This front ECU then controlls the relays for the lights based on the signal recieved from the dash. The fog lamp switch connects directly to the the ETACS-ECU , then based on the possition of the headlight switch the ETACS-ECU will tell the front ECU whether or not to ground the relay for the fog lights, turning them on. I have just bypassed that whole process.

Sure you can short them together with one wire but I like the control in the switch and I like the freedom to have them on or off when I see fit.



I did realize last night that there is a simpler way for me to build my circuit and save a few bucks. I'll try and come up with the schematic and parts list later today or tonight and figure out the total cost.

It could also be done with a small microcontroller more efficiently and you would lose the 2 second cap discharge wait and the unit would be smaller, but the cost wouldn't be any less, probably be even more. Not sure. I need to go to the store tonight and look at my options.

 

Thanks man....We are awaiting your response!

 

Ditto man, Or If you can start making them , i would Definatly buy one

 

i'm starting to like your method. can you describe how the microswitch would work?

 

alright, I'll make some

outside of the black box I would put it in it would work exacly like the one I put in my car did. I think the circuit I used in mine will be the cheapest, easiest way to do this and I can drop one of the relays. It will make for the least complex circuit.

I went to get pricing tonight after I picked my daughter up from daycare, but she wasn't as happy to go as I was so I had to cut the trip short. I got some info, but not enough. I'll nail it down for sure tomorrow.

 

i just show interest in the microswitch because you make it sound simpler and smaller... which i would value. but if everything else is cheaper and simpler etc. then i guess i'll explore that.

 

awesome, any chance you could take some step-by-step instructions/pics of putting the circuit(box) together? that would be great if you had the time!

 

Well the microcontroller would require programming too


The new ones will be MUCH smaller than the one I put in mine. I used some relays I had laying around for mine and they were not the smallest , and I have decided to do it with one less relay. And I found some smaller enclosures last night and refined my layout.

Yeah I think I could do that. So if someone wants one they aren't waiting on someone else to make it.

I'll go tonight and nail down the cost to make a few more and let you guys know what I would need to get out of it to make a few and ship them later this week or this weekend. Sorry its taking so long I really wanted to go last night I know I am enjoying running my fogs on the way to and from work

 

can't wait till i can do the same!

 

i would definently buy one

 

id buy one...